设计模式之工厂模式

一、简单工厂

package design.pattern.factory;

public class SimpleFactory {

    public static void main(String[] args) {
        SimpleFactory factory = new SimpleFactory();
        System.out.println(factory.produce(EmailMaker.class, "Lucy"));
        System.out.println(factory.produce(CallMaker.class, "Neo"));
    }
    
    /** 指定类型， 根据入参生成产品*/
    public Product produce(Class<?> cls, String param) {
        if (cls.isAssignableFrom(EmailMaker.class)) {
            return new EmailMaker().make(param);
        } else if (cls.isAssignableFrom(CallMaker.class)) {
            return new CallMaker().make(param);
        }
        return null;
    }
    
    
    /**-----------------------------------------------------------*/
    static class Product {
    }

    static class Email extends Product {
        @Override
        public String toString() {
            return "   this an Email";
        }
    }

    static class Call extends Product {
        @Override
        public String toString() {
            return "   this a Call";
        }
    }

    
    /**-----------------------------------------------------------*/
    interface Maker {
        public Product make(String type);
    }

    class EmailMaker implements Maker {

        @Override
        public Product make(String param) {
            System.out.println("Hi, " + param);
            return new Email();
        }
    }

    class CallMaker implements Maker {

        @Override
        public Product make(String param) {
            System.out.println("Hi, " + param);
            return new Call();
        }
    }

    

}

二、工厂方法

package design.pattern.factory;


public class FactoryMethod {
    
    public static void main(String[] args) {
        FactoryMethod factory=new FactoryMethod();
        System.out.println(factory.produceEmail("Lucy"));
        System.out.println(factory.produceCall("Neo"));
    }
    
    /**每个产品一个方法*/
    public Call produceCall(String param) {
        return (Call) new CallMaker().make(param);
    }
    
    public Email produceEmail(String param) {
        return (Email) new EmailMaker().make(param);
    }
    
    
    /**-----------------------------------------------------------*/
    static class Product {
    }

    static class Email extends Product {
        @Override
        public String toString() {
            return "   this an Email";
        }
    }

    static class Call extends Product {
        @Override
        public String toString() {
            return "   this a Call";
        }
    }

    
    /**-----------------------------------------------------------*/
    interface Maker {
        public Product make(String type);
    }

    class EmailMaker implements Maker {

        @Override
        public Product make(String param) {
            System.out.println("Hi, " + param);
            return new Email();
        }
    }

    class CallMaker implements Maker {

        @Override
        public Product make(String param) {
            System.out.println("Hi, " + param);
            return new Call();
        }
    }


}

 2.1 静态工厂：

　　　因为是内部类， 所以需要先 new FactoryMethod()

    public static Call produceCall(String param) {
        return (Call) new FactoryMethod().new CallMaker().make(param);
    }

三、抽象工厂

package design.pattern.factory;

public class AbstractFactorys {
    
    public static void main(String[] args) {
        AbstractFactorys factorys = new AbstractFactorys();
        
        System.out.println(factorys.new EmailFactory().work().make("Lucy"));
        System.out.println(factorys.new CallFactory().work().make("Neo"));
    }
    
    /**定制工厂，每个工厂只能生产指定产品*/
    /**-----------------------------------------------------------*/
    interface Factory{
        Maker work();        
    }
    
    class EmailFactory implements Factory{
        @Override
        public Maker work() {
            return new EmailMaker();
        }
    }
    
    class CallFactory implements Factory{
        @Override
        public Maker work() {
            return new CallMaker();
        }
    }

    
    
    /**-----------------------------------------------------------*/
    static class Product {
    }

    static class Email extends Product {
        @Override
        public String toString() {
            return "   this an Email";
        }
    }

    static class Call extends Product {
        @Override
        public String toString() {
            return "   this a Call";
        }
    }

    
    /**-----------------------------------------------------------*/
    interface Maker {
        public Product make(String type);
    }

    class EmailMaker implements Maker {

        @Override
        public Product make(String param) {
            System.out.println("Hi, " + param);
            return new Email();
        }
    }

    class CallMaker implements Maker {

        @Override
        public Product make(String param) {
            System.out.println("Hi, " + param);
            return new Call();
        }
    }

}

四、范型工厂

 　　可以统一构造相同属性。

package design.pattern.factory;

public class GenericFactory {

    public static void main(String[] args) {
        MobileRQ rq = GenericFactory.createRQ(MobileRQ.class);
        System.out.println(rq);
    }

    public static <T extends RQ> T createRQ(Class<T> cls) {
        try {
            T rq = cls.newInstance();
            rq.setAccessTocken("a341p28y^&s");
            rq.setTimeStamp(String.valueOf(System.currentTimeMillis()));
            return rq;
        } catch (Exception e) {
            e.printStackTrace();
        }
        return null;
    }

    static class RQ {
        private String accessTocken;
        private String timeStamp;

        public String getAccessTocken() {
            return accessTocken;
        }

        public void setAccessTocken(String accessTocken) {
            this.accessTocken = accessTocken;
        }

        public String getTimeStamp() {
            return timeStamp;
        }

        public void setTimeStamp(String timeStamp) {
            this.timeStamp = timeStamp;
        }

        @Override
        public String toString() {
            return "RQ [accessTocken=" + accessTocken + ", timeStamp=" + timeStamp + "]";
        }
    }

    static class PCRQ extends RQ {
        /* something else */
    }

    static class MobileRQ extends RQ {
        /* something else */
    }

}